Imaging ivc filter catheter and method

ABSTRACT

A combined multi-lumen central access catheter with a fixedly coupled filter, and an imaging modality to conduct intravascular imaging and ascertain a state of capture of thrombus in the filter and a method of capturing thrombus in a filter mounted on a catheter and imaging the state of capture of thrombus in the filter.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a continuation of U.S. patent application Ser. No.13/918,601, filed Jun. 14, 2013, now U.S. Pat. No. 9,039,729; which is acontinuation of U.S. patent application Ser. No. 13/735,810, filed Jan.7, 2013, now U.S. Pat. No. 9,039,728; which is continuation-in-part ofU.S. patent application Ser. No. 12/684,839, filed Jan. 8, 2010, nowU.S. Pat. No. 8,613,753; which is a continuation-in-part of U.S. patentapplication Ser. No. 11/849,225 filed Aug. 31, 2007, now U.S. Pat. No.8,668,712; and claim the benefit of priority from U.S. ProvisionalApplication No. 61/668,308, filed Jul. 5, 2012; each of which are herebyincorporated by reference in their entirety and from which priority ishereby claimed.

BACKGROUND OF THE INVENTION

The present invention pertains generally to the field of vascularfilters for capturing embolic material in the blood flow.

The accepted standard of care for patients with venous thromboembolism(VTE) is anticoagulant therapy. Inferior vena cava (IVC) filters arereserved for those patients who fail anticoagulant therapy, or have acomplication or contraindication to anticoagulant therapy. Until theearly 1970's, the only method of IVC interruption was surgical, eitherby clipping, ligation or plication. The first clinical experience of anendoluminally-placed device to interrupt IVC flow was reported byMobin-Uddin et al. in 1969. However, it was not until the introductionof a stainless steel umbrella-type filter by Greenfield et al. in 1973that an effective method of endoluminally trapping emboli whilesimultaneously preserving IVC flow became possible. Indeed, for manyyears, the Greenfield filter set a benchmark by which newer filters weremeasured. Early generations of filters were inserted by surgicalcut-down and venotomy. Eventually filters were able to be insertedpercutaneously: initially through large 24 Fr sheaths, though newergenerations of filters are able to be delivered through 6 Fr systems.

Despite the safety and efficacy of modern day filters, systemicanticoagulation remains the primary treatment for VTE. Eitherunfractionated or low molecular weight heparin followed by three monthsof oral anticoagulation in patients with proximal deep venous thrombosis(DVT) is approximately 94% effective in preventing pulmonary embolism(PE) or recurrent DVT. The routine placement of IVC filters in additionto anticoagulation in patients with documented DVT was investigated byDecousus et al. in a randomized trial. Decousus H, Leizorovicz A, ParentF, et al. A clinical trial of vena cava filters in the prevention ofpulmonary embolism in patients with proximal deep-vein thrombosis. NEngl J Med 1998; 338:409-415. This study revealed that the use of apermanent filter in addition to heparin therapy significantly decreasedthe occurrence of PE within the first 12 days compared to those withouta filter. However, no effect was observed on either immediate orlong-term mortality, and by 2 years, the initial benefit seen in thegroup of patients with filters was offset by a significant increase inthe rate of recurrent DVT.

Despite the efficacy of anticoagulant therapy in the management of VTE,there are certain situations and conditions in which the benefits ofanticoagulation are outweighed by the risks of instituting such atherapy. These include contraindications and complications ofanticoagulant therapy. In such circumstances, there may be absolute orrelative indications for filter insertion

Currently, there are several different types of permanent cava filtersthat are FDA approved. These include the Bird's Nest filter (CookIncorporated, Bloomington, Ind.), Vena Tech LGM filter (B. Braun,Bethlehem Pa.), Vena Tech LP (B. Braun), Simon Nitinol filter (Bard,Covington, Ga.), Titanium Greenfield filter (Boston Scientific, NatickMass.), Over-the-Wire Greenfield filter (Boston Scientific), TrapEasefilter (Cordis Corp.), SafeFlo filter (Rafael Medical Technologies,Inc.), and the Günther Tulip filter (Cook Medical).

Well-founded concerns over the long-term complications of permanent IVCfilters, particularly in younger patients in need of PE prophylaxis witha temporary contraindication to anticoagulation, has led to thedevelopment of temporary and retrievable filters. Temporary filtersremain attached to an accessible transcutaneous catheter or wire. Thesehave been used primarily in Europe for PE prophylaxis duringthrombolytic therapy for DVT. Currently these devices are not approvedfor use in the United States. Retrievable filters are very similar inappearance to permanent filters, but with modifications to the cavalattachment sites and/or hooks at one end that can facilitate theirremoval. Retrievable filters are currently available in the UnitedStates, examples of these as set forth in Endovascular Today's 2012Buyer's Guide include the ALN Optional Filter (ALN), Option (ArgonMedical Devices) Gunther Tulip (Cook Inc.), Celect and Opt Ease (CordisCorp.), and Eclipse and Meridian nitinol filters (Bard PeripheralVascular, Tempe, Ariz.). 2012 Buyer's Guide, Endovascular Today 2011;Dec.: 98. The time limit of retrievability is in part dependent on therate of endothelialization of the device, which typically occurs within2 weeks. However, differences in design may extend the time period inwhich the filter may be safely retrieved.

Currently no consensus exists as to which patients have an indicationfor a retrievable filter. However, it is generally accepted thatpatients at high risk for pulmonary embolism or with documented PE andwith a temporary contraindication to anticoagulation are candidates.

Certain circumstances preclude the placement of a filter in theinfrarenal IVC. This includes thrombus extending into the infrarenalIVC, renal vein thrombosis or pregnancy. The safety of suprarenalplacement of IVC filters is well documented, with no reported instancesof renal dysfunction and no differences in the rates of filtermigration, recurrent PE or caval thrombosis.

The rate of upper extremity DVT is on the rise. This is predominantlydue to an increasing number of patients having short- and long-termupper extremity central venous access catheters. In one study, 88% ofpatients found to have an upper extremity DVT had a central venouscatheter present at the site of thrombosis at the time of diagnosis orwithin the previous two weeks. Pulmonary embolism may complicate upperextremity DVT in 12-16% of cases. In patients who have such acomplication or contraindication to anticoagulation, a filter can besafely placed immediately below the confluence of the brachiocephalicveins. However, misplacement of an SVC filter is theoretically morelikely than with an IVC filter because of the relatively short targetarea for deployment.

The most common imaging modality used for filter insertion isfluoroscopy, performed either in an interventional suite or an operatingroom. Bedside placement of filters has inherent advantages, particularlyfor critically ill patients in intensive care settings where transportcan be avoided. Portable fluoroscopy, surface duplex ultrasound andintravascular ultrasound (IVUS) have all been used to assist withbedside filter placement.

Vena cava filter placement frequently occurs concomitantly with centralaccess line placement or in critically ill patients that already have acentral access line in place. Heretofore, however, there have been nodevices which combine the function of a central access catheter and aremovable vena cava filter.

SUMMARY OF THE INVENTION

The present invention relates to multi-lumen central access catheterhaving a proximal end and a distal end thereof relative to thelongitudinal axis of the catheter, a vena cava filter near the distalend of the central access catheter, at least one of a port proximal thevena cava filter or a port distal the vena cava filter. The proximal anddistal ports, which may be positioned entirely or partially distant froman open area bounded by the filter member, and lumens associatedtherewith, are also open to fluid flow to provide means for introducingfluids, such as an anticoagulant, thrombolytic or other bioactiveagents, contrast medium, blood transfusions, intravenous fluids or othermedications. Alternatively, the proximal and distal ports may be usedfor withdrawal or evacuation of fluids or other material through thecatheter.

The present invention may be configured for either a femoral approach ora jugular approach to the inferior vena cava. Vena cava filters aretypically deployed infrarenaly, but may also be deployed suprarenaly. Itwill be understood that within the inferior vena cava blood flow issuperior, i.e., toward the patients head. Thus, in all embodiments, thevena cava filter will be positioned so that it opens inferiorly, i.e.,away from the patient's head and toward the direction of the blood flow.It will be appreciated, therefore, that in the present invention, thevena cava filter will have a different axial orientation on the centralaccess catheter depending upon whether the device is intended for use ina femoral approach or a jugular approach.

Accordingly, it is an objective of the present invention to provide amulti-lumen catheter coupled to a vena cava filter that is useful bothas a central venous access catheter for administration of intravenousfluids, bioactive agents, contrast agents, flushing agents, pressurizedfluids for mechanical thrombolysis and/or withdrawal of blood samplesand for capture of thrombus or emboli.

Another aspect of the present invention is to provide a filter geometryin which the proximal portion of the filter, relative to the axis ofblood flow, has larger interstitial openings to permit thrombus orembolic material to flow into the filter, while the distal portion ofthe filter, again relative to the axis of blood flow, has relativelysmaller interstitial openings that capture the thrombus or embolicmaterial within the filter. Another way to view this aspect is that thestructure of the filter includes a greater open surface area exposed tothe flow of embolic material into the filter at its proximal end, whilethe distal end has smaller open surface area exposed to the flow ofembolic material to capture the embolic material in the distal end ofthe filter member. More specifically, regardless of whether the presentinvention is delivered by a jugular approach or a femoral approach, thefilter geometry is such that the larger interstitial openings of thefilter are positioned inferiorly along a longitudinal axis of thefilter.

Each of the foregoing embodiments of the present invention may furtherbe adapted for use with an imaging modality to facilitate intravascularimaging beyond or within the region of the filter member. In thismanner, as opposed to the prior art, the condition of the filter membermay be visualized from within the filter member, rather than via atraditional external imaging modality such as fluoroscopy, venography,or ultrasound. Additionally, in some embodiments, the imaging modalitymay pass entirely through the distal tip of the multi-lumen catheter,and enable an operator to use the intravascular imaging modality tovisualize the origins of the renal veins. This could allow the operatorto place the catheter without use of external imaging (i.e. fluoroscopy,trans-abdominal duplex ultrasound, CT, etc.).

Generally, intravascular imaging systems utilize a sheath through whicha signal is transmitted and received. In the present invention, themulti-lumen catheter with associated filter member may serve as thesheath for introduction of an intravascular imaging system, permittingimproved imaging of the condition of the filter member while in use. Inparticular, the use of an intravascular imaging system with themulti-lumen catheter with associated filter member will permit a medicalprofessional to monitor the condition of the filter member, and utilizeappropriate techniques to lyse a collected thrombus. Because of theimproved imaging, the lysing techniques may be more specifically andaccurately targeted, as compared to lysing techniques applied withoutthe benefit of imaging the condition of the filter member. In other,alternative, embodiments, the intravascular imaging system may alsoenable a medical professional to visualize the filter catheter forplacement within a patient.

Some non-limiting examples of imaging systems include intravascularultrasound (IVUS), optical coherence tomography (OCT), side looking OCT,ultrasound, thermography, IR imaging, Florence imaging, luminescentimaging, MRI, videography, photoacoustic, and other similar imagingtechnologies. These systems may permit 360 degree imaging, or be sidelooking and rotatable to image through 360 degrees. In one embodiment,the system generally includes an imaging core drive cable and an imagingprobe. The imaging probe may be a tip, cone, and/or the like disposed ata distal end of the imaging core drive cable, wherein the imaging probeand/or the drive cable are operably connected to an external system foroperating the imaging system.

In one embodiment, the imaging probe may be disposed within a portion ofthe central lumen bounded by the filter member. Thus, the imaging probemay be operated to help a user detect the presence of a thrombuscaptured by the filter member. Further, the imaging probe may also helpdetect the size and/or position of a captured thrombus. The imagingprobe may be rotated and/or translated within the lumen, so as to permitimaging of the entire filter member. Alternatively, the imaging probemay be adapted to permit 360 degree imaging through the wall of thecatheter lumen without requiring rotation. In a further embodiment, theimaging probe may be adapted to permit imaging of the length of thefilter member without distal or proximal translation. Preferably, theimaging probe is operable to image the filter member in an expandedstate.

In another embodiment, the imaging system may be disposed within a lumenof a multi-lumen sheath associated with a multi-lumen or single lumenfilter catheter.

In one embodiment, the position of the imaging probe relative to thefilter member is determined. In one embodiment, the imaging probe mayfurther comprise a radiopaque material to permit external imaging of theprobe to determine its location relative to the filter. In analternative embodiment, the drive cable may have measured markingsdisposed thereon to permit determination of the position of the imagingprobe relative to the filter, based on the relationship between themarkings on the drive cable and the conduit into which the imaging probeand drive cable are inserted.

In order to monitor the condition of the filter member, the imagingprobe may transmit and receive an imaging signal through a wall of thelumen. The imaging signal may depend upon the particular imaging systemutilized, and generally comprises a transmitted signal, wave, energy, orthe like that is emitted from the imaging probe in order to image orvisualize the filter member. In one embodiment, the relevant portion ofthe lumen is a section of the catheter body bounded by the proximal anddistal ends of the filter member. The dimensions and/or material of anyor all of the catheter body may be selected to maximize imaging signaltransmission and/or imaging signal clarity.

Alternatively, in some embodiments the filter may be attached to an endof a single or a multi-lumen catheter. In these embodiments, the regionbounded by the proximal and distal ends of the filter is open and freeof imaging obstruction.

Generally, the imaging system may be used with the filter member tomonitor the condition of the filter member and to capture a thrombuswithin a blood vessel. This may be accomplished by introducing themulti-lumen catheter, having the filter member coupled thereto, into theblood vessel. The catheter may then be deployed within the blood vesselsuch that the filter has an enlarged diametric opening facing apatient's blood flow. The imaging system may then be translated througha lumen of the multi-lumen catheter and be operable to image orvisualize the condition of the filter member. Alternatively, the imagingsystem may be used to visualize the filter catheter to assist a medicalprofessional in placement of the filter catheter within a patient.

In another embodiment, the imaging system may be used with a multi-lumensheath coupled to a filter catheter, such that the imaging system isdisposed within a lumen of the multi-lumen sheath.

In one embodiment disclosed herein is a method of capturing thrombuswithin a blood vessel, comprising the steps of: introducing a catheterhaving a filter member coupled thereto; deploying the catheter within ablood vessel such that the filter has an enlarged diametric openingwhich opens facing a patient's blood flow; and imaging the filter memberwith an imaging system operable to detect a condition of the filtermember.

In one embodiment disclosed herein is a multi-lumen filter catheter,comprising: a multi-lumen catheter body having a plurality of lumens; afilter member coupled to the catheter body; and an imaging systemoperable to detect a condition of the filter member.

In one embodiment disclosed herein is a medical device, comprising: acatheter body having a filter member coupled to the catheter body; amulti-lumen sheath, wherein the catheter body is disposed within a lumenof the multi-lumen sheath; and an imaging system operable to detect acondition of the filter member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a central venous access vena cava filtercatheter in accordance with a first embodiment of the present inventionwith the vena cava filter in an unexpanded state.

FIG. 2 is a side elevational view of a central venous access vena cavafilter catheter in accordance with the first embodiment of the presentinvention.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 2.

FIG. 6 is a perspective view of a central venous access vena cava filtercatheter in accordance with a second embodiment of the present inventionillustrating the vena cava filter in an unexpanded state.

FIG. 7 is a side elevational view of a central venous access vena cavafilter catheter in accordance with the second embodiment of the presentinvention.

FIG. 8 is a cross-sectional view taken along line 8-8 of FIG. 7.

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 7.

FIG. 10 is a cross-sectional view taken along line 10-10 of FIG. 7.

FIG. 11 is a cross-sectional view taken along line 11-11 of FIG. 7.

FIG. 12 is a perspective view of the central venous access vena cavafilter catheter of FIG. 1 illustrating the vena cava filter in adiametrically expanded state.

FIG. 13A is a perspective view of a vena cava filter member inaccordance with a first embodiment thereof.

FIG. 13B is a first side elevational view thereof.

FIG. 13C is an end elevational view thereof.

FIG. 13D is a second side elevational view thereof.

FIGS. 14A-14H are perspective views of alternative embodiments of a venacava filter member in accordance with the present invention.

FIGS. 15A-15H are fragmentary side elevational views of the alternativeembodiments of the vena cava filter member illustrated in FIGS. 14A-14H.

FIG. 16A is a side elevational view of the vena cava central linecatheter in its undeployed state.

FIG. 16B is a side elevational view of the vena cava central linecatheter in its deployed state.

FIG. 17 is a side elevational view of a vena cava filter member in itsexpanded state in accordance with one embodiment of the presentinvention.

FIG. 18 is a perspective view of a vena cava filter member in itsexpanded state in accordance with an alternative embodiment of thepresent invention.

FIG. 19 is a perspective view of a vena cava filter member in itsexpanded state in accordance with yet another embodiment of the presentinvention.

FIG. 20 is a perspective view of a vena cava filter member in itsexpanded state in accordance with still another embodiment of thepresent invention.

FIGS. 21A and 21B are perspective views of a vena cava filter membermounted at a distal end of a central line catheter having a distalballoon.

FIGS. 22A and 22B are perspective views of an alternative embodiment ofa vena cava filter member mounted at a distal end of a central linecatheter having a distal balloon.

FIG. 23 is a side cross sectional view of an embodiment of the vena cavafilter member mounted at a distal end of a central line catheter in itsexpanded state, further comprising an imaging modality disposed within alumen of the catheter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the accompanying Figures like structural or functional elements aredesignated by like reference numerals, e.g., 16, 116, 216, 316, 416represent similar structural or functional elements across differentembodiments of the invention. With particular reference to FIGS. 1-5,according to a first embodiment of the invention, there is disclosed acentral venous access filter (“CVAF”) 10 that is composed generally of amulti-lumen central venous access catheter body 12 having a proximalport 32 associated with a first lumen 44 and a distal port 34 associatedwith a second lumen 42, a filter member 16, having a first end 18 and asecond end 20, is positioned generally intermediate the distal port 34and the proximal port 32 and is generally concentric relative to thecatheter body 12. An outer sheath 22 is concentrically disposed over thecatheter body 12 such that relative movement of the catheter body 12 andthe outer sheath 22 either exposes the filter member 16 or captures thefilter member 16 within the outer sheath 22. The outer sheath 22terminates in an annular opening at a distal end thereof and at firsthub member 225 as depicted in FIGS. 16A and 16B. The proximal hub 225will be described more fully hereinafter. The catheter body 12 extendsthrough a central bore in the proximal hub 225 and passes through acentral lumen of the outer sheath 22. A second hub member 227, asdepicted in FIGS. 16A and 16B, is coupled to a proximal end of thecatheter body 12. The second hub member 227 and the first hub member 225are removably engageable with each other as will also be describedfurther hereinafter.

Depending upon the orientation of the filter member 16, the first end 18or the second end 20 may either be fixed or moveable relative to thecatheter body 12. Alternatively, as will be discussed furtherhereinafter, the filter member 16 may have only a first end 18 which isfixed to the catheter body 12

To facilitate percutaneous introduction of the inventive CVAF 10, aphysician may optionally elect to employ an introducer sheath (notshown) as vascular access conduit for the CVAF 10. The presence of thefilter member 16 at the distal end of the catheter body 12 creates aregion of relatively lower flexibility and the practitioner maydetermine it beneficial to employ an introducer sheath for vascularaccess.

As used in this application, unless otherwise specifically stated, theterms “proximal” and “distal” are intended to refer to positionsrelative to the longitudinal axis of the catheter body 12. Those skilledin the art will understand that the catheter body 12 has a distal endwhich is first inserted into the patient and a proximal end whichopposite the distal end. Additionally, the terms “inferior” or“inferiorly” are intended to refer to the anatomic orientation of beingin a direction away from the patient's head while the terms “superior”or “superiorly” are intended to refer to the anatomic orientation ofbeing toward the patient's head.

The multi-lumen aspect of the inventive central venous access filtercatheter 10 is shown more clearly in FIGS. 2-5. The catheter body 12 hasa proximal section 13 and a distal section 14. which is longitudinallyopposite the proximal section 13, and which may have a relativelysmaller diametric profile than the proximal section 13. As describedabove, the first lumen 44 terminates at the proximal port 32, while thesecond lumen 42 terminates at the distal port 34. A central guidewirelumen 30 may be provided that extends the entire longitudinal length ofthe catheter body 12 and terminates at the distal end of the catheterbody 12 at a distal guidewire opening 31 that permits the catheter bodyto track along a guidewire during a procedure. The central guidewirelumen 30 may also be used to introduce fluids, such as bioactive agents,intravenous fluids or blood transfusions.

Additionally, at least one of a plurality of infusion lumens 40 areprovided, each having at least one infusion port 36 that passes througha wall of the catheter body 12. Bioactive agents, flushing fluids forflushing or under elevated pressures for mechanical thrombolysis ofthrombus in the filter member 16, contrast agents or other fluids may beinfused through the infusion lumens 40 and out of the at least oneinfusion port 36 to pass into the patient's venous system for eitherlocal or systemic effect. In accordance with one embodiment of theinvention, plural infusion ports 36 are provided with multiple ports 36being provided in communication with a single infusion lumen 40 andspaced along a longitudinal axis of the catheter body 12. Additionally,plural infusion ports 36 may be provided in a circumferentially spacedmanner to provide for fluid infusion at points spaced around thecircumference of the catheter body 12. In this manner, fluid infusion isprovided along both the longitudinal axis and the circumferential axisof the catheter body 12 within the spatial area defined by and boundedby the filter member 16. Because the plural infusion ports 36communicate with the spatial area defined by and bounded by filtermember 16, fluids introduced through the infusion lumens 40 are directedimmediately at thrombus caught within the filter member 16. This permitsthrombolytic agents, high pressure mechanical thrombolysis using apressurized saline flush to be introduced directly to the situs ofthrombus capture within filter member 16. Alternatively, thermal,ultrasound or other types of thrombolysis may be employed to disruptthrombus captured by the filter member 16. For example, the annularspace between the outer sheath 22 and the catheter body 12 may be usedto introduce a thrombolytic to the filter and shower the filter todisrupt thrombus caught by the filter member 16. Additionally, theballoon depicted in FIGS. 21 and 22 may be positioned adjacent thefilter member 16 and be provided with plural openings oriented in thedirection of the filter member 16 to facilitate thrombolysis.

It will be understood, by those skilled in the art, that alternativearrangements of the first lumen 44, the second lumen 42, the guidewirelumen 30, or the infusion lumens are possible and contemplated by thepresent invention. The number and arrangement of lumens in the catheterbody 12 is a function of the desired number of operable ports passingthrough the walls of the catheter body 12, the relative position of theoperable ports, the desired position and geometry of the guidewire lumen30, the desired longitudinal flexibility of the catheter body 12, thedesirable degree of kink resistance of the catheter body 12, and otherfactors which are known to one of ordinary skill in the catheter arts.

While the present invention is not limited to specific dimensional sizesof either the catheter body member 12, the outer sheath 22, lumendiameter or port dimension, an exemplary outer diameter size of theouter sheath 22 is between 8 Fr (2.7 mm) and 9 Fr (3.0 mm) while anexemplary outer diameter size of the catheter member 12 is between 6 Fr(2.0 mm) and 7 Fr. A diametric transition taper 15 may be providedbetween the proximal portion 13 and the distal portion 14 of thecatheter body 12 corresponding to the thickness of the filter member 16.In this manner, the outer surface of the filter member 16 issubstantially co-planar with the outer diameter of the proximal portion13 of the catheter body 12 about its entire circumference.Alternatively, the catheter body member 12 may have a constant diameterand the filter member 16 coupled to an outer surface of the catheterbody member 12, with the outer sheath 22 having a luminal diametersufficient to fit over the filter member 16. Moreover, the fixed firstend 18 of filter 16 is positioned adjacent and in abutting relationshipwith the diametric transition 15, while the moveable second end 20 offilter member 16 is concentrically positioned around the distal section14 of catheter body 12 and is reciprocally moveable thereupon toaccommodate diametric expansion of the filter member 16. Lumen diameterand port dimension are a function of design requirements and arevariable depending upon the desired purpose and function of the lumen orport, e.g., pressure sensing, infusion, evacuation, guidewire, flowsensing, or flow conduit.

In order to aid a physician in visualizing the CVAF 10 in vivo, at leastone radio-opaque or other viewable marker may be provided. A firstmarker 24 is provided at the distal end of the outer sheath 22 and asecond marker 26 may be provided at a distal tip 33 of the catheter body12. It will be understood that when the outer sheath 22 is in itsnon-retracted delivery position, that the filter 16 will be covered andthe marker 24 and the second marker 26 will be adjacent or in closeproximity with one another. Alternatively, the outer sheath 22 may,itself, be made of or include a radio-opaque or other viewable material,such as a metal braid or metal reinforcement within or applied to apolymeric sheath. The first and second markers 24, 26 or the material ofthe outer sheath 22 may enhance visualization of the CVAF 10 underfluoroscopy, ultrasound or other visualization or guidance technique.

FIGS. 6-11 illustrate a second embodiment of the CVAF 50. Unlike CVAF10, CVAF 50 does not include the central guidewire lumen 30 of CVAF 10.Rather, while the general construct of CVAF 50 is similar to that ofCVAF 10, a different configuration of the inner lumens is employed.

CVAF 50, like CVAF 10, consists generally of a multi-lumen centralvenous access catheter body 12 having a proximal port 32 associated witha first lumen 54 and a distal port 34 associated with a second lumen 58,a filter member 16, having a fixed first end 18 and a moveable secondend 20, is positioned generally intermediate the distal port 34 and theproximal port 32 and is generally concentric relative to the catheterbody 12. Use of the term “generally intermediate” is intended to meanthat at least a substantial portion of the filter member 16 residesintermediate the distal port 34 and the proximal port 32. Thus, thefilter member 16 may partially overlay either or both of the proximalport 32 or the distal port 34.

The catheter body 12 has a proximal section 13 and distal section 14,which is longitudinally opposite the proximal section 13 which may havea relatively smaller diametric profile than the proximal section 13. Asdescribed above, the first lumen 54 terminates at the proximal port 32,while the second lumen 58 terminates at the distal port 34. Anatraumatic tip 52 terminates the catheter body 12 at its distal end. Theatraumatic tip 52 preferably includes a radio-opaque marker to aid inpositional visualization of the distal end of the catheter body 12.

A plurality of infusion lumens 56 are provided, each having at least oneinfusion port 36, preferably plural infusion ports 36, that passesthrough a wall of the catheter body 12 and communicates with a spacedefined within an area bounded by the filter member 16. Bioactiveagents, flushing fluids, pressurized mechanical thrombolytic fluids, orother fluids may be infused through the infusion lumens 56 and out ofthe at least one infusion port 36 to pass into the space defined by thefilter member 16 and ultimately into the patient's venous system foreither local or systemic effect. In accordance with one embodiment ofthe invention, the each of the plural infusion lumens 56 are in fluidcommunication with plural ports 36 arrayed along both the longitudinalaxis and the circumferential axis of the catheter body. Thisconfiguration provides for fluid infusion along both the longitudinalaxis and the circumferential axis of the catheter body 12 and in directcommunication with the space defined by the filter member 16 thatcaptures thrombus.

The infusion lumens 56, the first lumen 54 and the second lumen 58 arebounded by and separated from each other by first catheter septum 51 andsecond catheter septum 56 which also aid in providing structural supportfor the catheter body 12. First catheter septum 51 is a generallydiametrically and longitudinally extending member that divides the firstlumen 54 from the second lumen 58 along the longitudinal axis of thecatheter body 12. Second catheter septum 56 may comprise a generallyU-shaped member that intersects the first catheter septum 51 at a loweraspect of the septum and is connected with an inner wall surface of thecatheter body 12 at upper aspects of the septum 51 to define twoinfusion lumens in lateral regions of the catheter body 12.

The filter member 16 has two general configurations. A firstconfiguration consists generally of two opposing generally open conicalsections formed by plural interconnected structural elements definingthe lateral surfaces of each open conical section, wherein the twoopposing generally open conical sections each have open bases facingeach other which are interconnected by a generally cylindrical sectionof the filter member 16. Each open conical section has an open base andan apex, wherein the apices project in opposing directions, with oneapex projecting proximally and another apex projecting distally relativeto the axis of the catheter. The plural interconnected structuralelements forming the lateral surfaces of each generally open conicalsection may be strut-like structural members extending generally axiallyalong the longitudinal axis of the filter member 16. The axiallyextending strut-like structural members may be linear members or may becurved members. The apices of each of the generally open conicalsections are formed either of a generally cylindrical collar that servesto couple the filter member 16 to the catheter body 12. The generallycylindrical collar is concentrically engaged about the catheter body 12and may be axially movable thereupon, or is formed by connectionsbetween adjacent pairs of longitudinal strut-like structural memberswhich circumscribe a circumference of the catheter body 12. Thegenerally cylindrical section of the filter member 16 is formed by agenerally open lattice of interconnected structural elements whichconnect the base of a first open conical section to the base of a secondopen conical section. The generally cylindrical section of the filtermember 16 lies in apposition with a vascular wall upon deployment of thefilter member 16 with a vascular lumen.

A second general configuration of the filter member 16 consistsgenerally of a single generally open conical section in which aplurality of longitudinal strut-like structural members form the lateralsurfaces of the conical section and are connected to a generallycylindrical collar which couples the filter member 16 to the catheterbody 12 at an apex of the generally open conical section. The base ofthe generally open conical section is formed by opposing ends of thelongitudinal strut-like structural members. A generally cylindricalsection of the filter member 16, formed of a generally open lattice ofinterconnected structural elements, extends from the longitudinalstrut-like structural members forming the base of the generally openconical section, to provide a region of the filter member 16 which is inapposition to the vascular wall upon deployment of the filter member.

One embodiment of the filter member 16 is illustrated in itsdiametrically expanded configuration in FIGS. 12-13D. In thisembodiment, filter member 16 consists generally of a first end 18 and asecond end 20, each of which consists generally of a tubular structurewhich is circumferentially positioned about a section of the catheterbody 12. One of the first end 18 and second end 20 are fixedly coupledto the catheter body 12, while the other is movable relative to thecatheter body 12. At least one of a plurality of first strut members 62,are coupled at their first end to the first end 18 of filter member 16and each extends axially relative to the longitudinal axis of thecatheter body 12. Each of the first strut members 62 is an elongatemember that, upon diametric expansion of the filter member 16, flaresaway from the central longitudinal axis of the catheter body 12, in agenerally tapered conical manner, and terminates in an end section 63that bends generally parallel to and along the longitudinal axis of thecatheter body 12. A plurality of second strut members 64 are coupled atan end to the second end 20 of filter member 16 and each extendsparallel relative to the longitudinal axis of the catheter body 12. Aplurality of third strut members 66 are coupled at ends thereof to anend of the filter member and each extends parallel relative to thelongitudinal axis of the catheter body 12.

It will be appreciated, by those skilled in the art, that the number ofstruts employed as the first strut members 62, the second strut members64 and the third strut members 66 forming the filter member 16 may beevenly distributed about a 360 degree circumference and define thelateral wall surfaces of the filter member 16. A circumferential member70 extends circumferentially to define a circumferential axis of thefilter member 16 and has a series of continuous undulations definingpeaks a series of peaks 75 and valleys 77 about the circumference offilter member 16. Each of the plurality of first strut members 62, theplurality of second strut members 64 and the plurality of third strutmembers 66 are coupled to the circumferential member 70 at differentpoints about its circumferential axis and intermediate the proximal end18 and the distal end 20 of the filter member 16. In its unexpandedstate the filter member 16 has a generally tubular shape, while in itsexpanded state the filter member 16 assumes one of the generalconfigurations discussed above, i.e., either oppositely extendinggenerally open conical sections or a single generally open conicalsection.

The plurality of first strut members 62 are preferably offset from eachother by approximately 120 degrees about the circumference of thecatheter body 12. The plurality of second strut members 64 are alsopreferably offset from each other by approximately 120 degrees. Finally,the plurality of third strut members 66 are also preferably offset fromeach other by approximately 120 degrees. Each of the plurality of firststrut members 62 couple at a junction 76 to the circumferential member70 at a peak thereof. Similarly, each of the plurality of third strutmembers 66 couple at junction 76 to the circumferential member 70 at apeak thereof. In this manner, a first strut member 62 and a third strutmember 66 are each coupled to circumferential member 70 at junction 76and, in this relationship, form a generally linear member that extendsalong the longitudinal axis of the catheter body and connects betweenthe proximal end 18 of the filter member 16 and the distal end 20 of thefilter member 16. Each of the second strut members 64 couple, at theirproximal ends to a valley 77 of the circumferential member 70 andconnects at a junction 79. Unlike the connections at junction 76 betweenthe plurality of first strut members 62 and the plurality of secondstrut members, in this embodiment of the filter member 16, there is nomember that connects to junction 79 and extends from the first end 18 ofthe filter member 16. In this configuration, the circumferential member70 assumes a generally circumferential tri-leaflet ring having threepeaks 75 and three valleys 77 which circumferentially circumscribe acentral opening 72 which faces inferiorly relative to the patient'sblood flow such that the blood flow first passes into the centralopening 72 and past the third strut members 66 and the second strutmembers 64 then past the first strut members 62.

To facilitate bending and folding of the circumferential member 70between the expanded and unexpanded states, generally U-shaped hingemembers 74 may be provided at each of the valleys 77 of thecircumferential member 70. It will be understood that each of theplurality of first strut members 62, plurality of second strut members64, plurality of third strut members 66 and the circumferential member70 are preferably fabricated of biocompatible materials, such as shapememory alloys, superelastic materials or elastic materials, including,without limitation, titanium, vanadium, aluminum, nickel, tantalum,zirconium, chromium, silver, gold, silicon, magnesium, niobium,scandium, platinum, cobalt, palladium, manganese, molybdenum and alloysthereof, such as zirconium-titanium-tantalum alloys,cobalt-chromium-molybdenum alloys, nitinol, and stainless steel.

FIGS. 14A-14H and corresponding FIGS. 15A-15H depict alternativeembodiments of the filter member 16, labeled 80, 90, 100, 110, 120, 130,140 and 150, respectively. Like filter member 16, each of filter members80, 90, 100, 110, 120, 130, 140 and 150 having a first end 18 and asecond end 20 that each consist of a generally ring-like structureintended to circumferentially couple to a catheter body 12 (not shown),with the first end 18 being fixed and the second end 20 beingreciprocally moveable axially along the distal portion 14 of catheterbody 12. Like filter member 16, each of the alternative filter memberembodiments depicted in FIGS. 14A-14H and 15A-15H, consist of aplurality of first strut members 81, 91, 101, 111, 121, 131, 141 and151, respectively, extending distally from the first end 18 of thefilter member and a plurality of second strut members 83, 93, 103, 113,123, 133, 143 and 153, respectively, extending proximally from thedistal end 20 of the filter member, with a diametrically expansiblecircumferential member 87, 97, 107, 117, 127, 137, 147, 157,respectively, interconnecting the distally extending strut members 81,91, 101, 111, 121, 131, 141 and 151, respectively, with the proximallyextending strut members 83, 93, 103, 113, 123, 133, 143 and 153. In thealternative embodiments of filter members 100, 110 and 120, at leastsome distally extending strut members and at least some of theproximally extending strut members form linear elements that extendalong the entire longitudinal axis of the respective filter member, withthe circumferential member being comprised of at least one undulating orserpentine ring structure.

In the alternative embodiments of filter members 80, 90, 130, 140 and150, a plurality of distally extending strut members are provided spacedapproximately 120 degrees apart from one and other about thecircumference of the filter members, and the distally extending strutmembers bifurcating once or twice distally in a generally Y-shapedmanner as in filter members 80, 130, 140 or 150, or the proximallyextending strut members bifurcating proximally in a generally Y-shapedmanner and interconnecting with the distally extending generallyY-shaped strut members to form a diamond-like pattern as in filtermember 90. In filter members 90 and 140, the circumferential member isformed by the diamond-like pattern formed by the intersection of theplurality of struts. In contrast, in filter members 80, 130 and 150, thecircumferential member is formed by at least one undulating orserpentine ring structure which is diametrically expansible. Asillustrated in filter members 110, 120 and 130, apical portions of eachundulating or serpentine ring structure is interconnected by aninterconnecting member 114, 124, 134, respectively, either with anadjacent ring structure, as in filter member 110 or to a distal end 20of the filter member itself. A longitudinally serpentine section 132 infilter 32 may be provided in conjunction with the interconnecting member134, to afford greater expansive properties to the circumferentialmember 137.

According to some embodiments particularly well-suited for placement byfemoral or other infrarenal approach, the filter member 16 ischaracterized by a generally conical filter member 16 having a greateropen surface area exposed to the flow of embolic material into thefilter at its proximal end, while the distal end has smaller opensurface area exposed to the flow of embolic material to capture theembolic material in the distal end of the filter member.

In other embodiments particularly well-suited for placement by a jugularor suprarenal approach, the filter member 16 is characterized by agenerally conical filter member 16 having a greater open surface areaexposed to the flow of embolic material into the filter at its distalend, which the proximal end of the filter member 16 has a smaller opensurface area exposed to the flow to capture smaller embolic material inthe distal end of the filter member 16.

Additionally, in all of the embodiments the filter member 16 isself-centering to provide proper apposition against the vascular wallsand centering within the lumen of a blood vessel. This maximizes theflow dynamics of the filter member 16 within the blood vessel forpurposes of capturing embolic material within the struts of the filterand centers the catheter body member 12 within the vascular lumen.

As noted above, the proximal 32 and distal 34 ports serve as means formeasuring flow rates or pressure differentials across the filter 16.This may be accomplished by including flow sensors and/or pressuretransducers 19 in operable association with each port 32, 34, with theassociated electrical connections to the flow sensors and/or pressuretransducers 19 passing through the respective lumens associated witheach port 32, 34 and terminating at the proximal end of the catheterbody 12. Where flow sensors 19 are employed, a single flow sensorassociated with proximal port 32, the distal port 34 or the distal endof outer sheath 22 may be sufficient to detect fluid flow rate at theposition of the catheter body 12. By providing a flow sensor at thedistal end of sheath 22, the clinician will be able to determine flowvelocity at the distal end of the outer sheath 22 prior to introducingthe catheter body 12 and make fine adjustments to the placement of thedistal end of the outer sheath 22 to ensure proper placement for thefilter member 16. Plural flow sensors 19 may be employed and operablyassociated with each of proximal port 32 and distal port 34 to sensechanges in flow velocity across the filter member 16. Alternatively, theflow sensors and/or pressure transducers 19 may reside in communicationwith the lumens respectively associated with each port 32, 34 at theproximal end of the catheter body 12, thereby eliminating the need forelectrical connectors resident with the associated lumens. Furthermore,wireless flow sensors and/or pressure transducers may be provided incommunication with each port 32, 34, and be operably coupled to a powersource and a transmitter to wirelessly transmit telemetry data from thetransducers to a wireless receiver in communication with thetransmitter, as is known in the art.

Alternatively, the proximal 32 and distal ports 34 may be used formonitoring or sensing other conditions in the body that are detectablein the blood. For example, analyte sensors may be introduced to eitherthe lumens communicating with the proximal 32 or distal ports 34 or tothe ports themselves to monitor and/or sense chemical or biochemicalconditions in the body. An example of this application is monitoring orsampling blood glucose levels for diabetes control. Further, theproximal 32 and distal ports 34 may be used for fluid infusion or forwithdrawal or evacuation of fluids or other material through thecatheter body 12. In this later instance, where the proximal port 32 ispositioned to underlay the filter member 16, thrombus collected in thefilter member 16 may capable of being lysed, either by thrombolysisthrough the infusion ports 36 or under the influence of thermal ormechanical lysis, such as by introducing a laser, ultrasound or othersystem capable of lysing thrombus, which may be introduced through thelumen communicating with the proximal port 32, or the distal port 34 orthe guidewire lumen 30, or introduced separately from the CVAF 10,positioned within the space bounded by the filter member 16, lysingthrombus collected in the filter member 16 and evacuating the lysedthrombus through the proximal port 32

It is known that flow rate increases proximally within the venoussystem. For example a flow rate of 1 L/min is typical in one femoralvein, increases to 2 L/min in the inferior vena cava and increasinganother 0.7 to 1 L/min proximate the renal veins. Knowing the typicalflow velocities in vessels of different transverse cross-sectionalareas, coupled with a flow sensor 19 associated with the multi-lumencatheter body 12 may serve to supplement or replace the requirements forfluoroscopy or sonography in placement of the CVAF 10, 50.

Other sensors, such as, for example, chemosensors, color sensors,electrical sensors or biosensors, may be employed in lieu of or inaddition to pressure transducer and/or a flow sensor 19 in order todetect other changes or conditions within the patient's vasculature. Forexample, color sensors exist that sense color changes in thrombus, suchcolor changes may be displayed and interpreted by the medicalpractitioner as an indication of thrombus staging. Analyte sensors, sucha as a glucose sensor or an oxygen saturation sensor may also beemployed.

The filter member 16, or its alternative embodiments described above,may be fixed to the catheter body 12 or may be removably coupled to thecatheter body 12 for deployment as either a permanent filter or as atemporary and retrievable vena cava filter. Removable coupling of thefilter member to the catheter body 12 may be accomplished with a varietyof release and retrieval mechanisms operably associated the catheterbody 12 and proximate the diametric transition 15. Non-limiting examplesof such release and retrieval mechanisms include a wire release thatengages with a the first end 18 of the filter, a cooperating indexeddetent and projection interaction between the catheter body 12 and thefirst end 18 of the filter, such as a detent in the proximal end of thefilter and a cooperating projection in the multi-lumen catheter that ispositionally indexed to the detent and releasable from the detent, or,alternatively, a helical slot or threads may be formed in the proximalend 18 of the filter and indexed and cooperating projection in themulti-lumen catheter than permits engagement and disengagement with thehelical slot or threads.

In use, an introducer sheath is first placed into the body in a normalmanner for introducing a central venous line, such as by the Seldingertechnique. Specifically, after accessing a vein using a large boreneedle, under local anesthesia, a guidewire is inserted through theneedle bore and passed into the vein. Once the guidewire is positioned,the needle is withdrawn, and a dilator together with the introducersheath introduced over the guidewire. Once the introducer sheath ispositioned at a desired location within the venous system underradiography, the dilator may be removed from the patient. Radiopaquemarkers associated with the introducer sheath may be employed to assistin positional visualization of the distal end of the introducer sheath.The outer sheath 22 covering the filter 16 is removed while introducingthe filter member 16 and catheter body 12 into the introducer sheath.The outer sheath 22 constrains the filter member 16 during its passagethrough the introducer sheath and positioning the distal end of thecatheter within the patient's vasculature. Once the distal end of thecatheter body 12 reaches the distal end of the introducer sheath, thefilter is deployed. If the filter therapy alone is desired, the filtermember 16 is detached from the catheter body 12 and the catheter body12, introducer sheath and guidewire is withdrawn from the patient. Whereboth central venous access and filter therapy is desired, the introducersheath and catheter body 12 with the filter member 16 is left in thepatient until withdrawal is required.

Retrieval and removal of a detached filter member 16 is accomplishedusing a second procedure under local anesthesia which substantiallyreplicates the placement of the CVAF, with a capture sheath (not shown),similar to introducer sheath, being introduced, a retrieval catheterbeing introduced through the sheath, and engaging the filter member 16,then withdrawn into the capture sheath to collapse the filter member 16,with the entire assembly of the filter member 16, catheter body 12,outer sheath 22 and guidewire, if used, is withdrawn from the patient.

As depicted in FIGS. 16A and 16B, which depict the undeployed state(FIG. 16A) and the deployed state (FIG. 16B) of the filter member 216,respectively, common to each of the embodiments of the present invention200 is an inner catheter 214 that carries the vena cava filter 216 at adistal end thereof. The inner catheter 214 is concentrically andreciprocally engaged within an outer sheath 222 such that relative axialmovement of the inner catheter 214 and the outer sheath 222 eitherexposes the vena cava filter 216 for deployment or captures the venacava filter 216 for retrieval. A first hub member 225 is coupled to aproximal end of the outer sheath 222 and a second hub member 227 iscoupled to a proximal end of the inner catheter 214. First hub member225 and second hub member 227 are engageable, such as by a threaded,bayonet, snap fit, friction fit or interference fit fitting, to securethe inner catheter 214 within the outer sheath 222 and restrict relativeaxial movement of the two elements after deployment of the vena cavafilter 216. A flush line 229 communicates with the first hub member 225and is in fluid communication with a luminal space within the outersheath 222. A plurality of fluid lines 231, 233, 235, 237 communicatewith the second hub member 227 and are each in fluid communication withone of the plural lumens within the inner catheter member 214, e.g.,lumens communicating with the proximal, distal or infusion ports (notshown). A distal tip 26 is provided at a distal end of the innercatheter.

A jugular approach necessitates that the catheter be introducedretrograde relative to the vector of blood flow within the vena cava,i.e., the catheter is introduced through the jugular vein and directedinferiorly toward an infrarenal position. Additionally, since the bloodflow opposes the distal end of the catheter and passes toward theproximal end, the vena cava filter must open inferiorly such that itslargest diametric section in apposition to the vessel walls opens towardthe distal end of the catheter rather than toward the proximal end ofthe catheter as with the femoral approach.

FIGS. 17-20 depict alternative embodiments of vena cava filter membersin accordance with the present invention. FIG. 17 illustrates a filterorientation for a femoral approach, while FIGS. 18-20 illustrate afilter orientation for a jugular approach. As illustrated in FIG. 17,filter member 216 defines a relatively larger volume open space 201 anda relatively smaller volume open space 203. Open spaces 201 and 203 arebounded by structural members of the filter member 216 and are both opentoward the direction of blood flow indicated by arrow 5, with largeropen space 201 being relatively upstream the blood flow relative tosmaller open space 203 in both the femoral or the jugular orientation offilter member 216.

As with all previous embodiments described of the filter member, filtermember 216 is formed of plural interconnected structural elements. Inaccordance with the preferred embodiments of the filter members of thepresent invention, and as particularly exemplified by filter member 216,the filter member has a first end 218 and a second end 220, at least oneof which is attached to the distal section 214 of the catheter body 212.First structural members 217 extend generally axially, either proximallyas shown in FIG. 17 or distally as shown in FIG. 18, along thelongitudinal axis of the filter member 216. Again, it is understood thatuse of the terms “proximal” or “proximally” and “distal” or “distally”are intended to refer to positions relative to the longitudinal axis ofthe catheter body 212. The first structural members 217 are connected toeither the first end 218 or the second end 220 of the filter member 216.Second structural members 219 are connected to the first structuralmembers 217 at an end of the first structural members 217 which isopposite that connected to either the first end 218 or the second end220 of the filter member 216. In accordance with a preferred embodimentof the invention, the second structural members 219 form at least twosuccessive zigzag shaped structures which are connected to an end of thefirst structural members and at opposing apices 223 to form conjoinedring-like structures about the circumference of the filter member 216.In this manner the second structural members 219 generally definelattice-like pattern upon diametric expansion of the filter member 216.The lattice-like pattern formed by the second structural members 219projects axially along the longitudinal axis of the catheter 214tapering to form at least one petal-like projection 225 that terminatesin a terminal apex member 227. As will be appreciated by those skilledin the art, FIG. 17 depicts three petal like projections 225, with onebeing behind the plane of the figure and, therefore, not shown. Each ofthe petal-like projections 225 act to engage and oppose vascular wallsurfaces to seat the filter member 216 against the vessel wall, andcenter the filter member and catheter 214 within the vascular lumen. Asillustrated in FIG. 17, third structural members 221 are provided andare connected to each of the terminal apex members 227 and extendaxially relative to the catheter 214 and connect with a second end 218of the filter member 216.

In the embodiment illustrated in FIG. 17, which is an orientation of thefilter member 216 for a femoral approach, and in the embodimentillustrated in FIG. 19, which is an orientation of the filter member 216for a jugular approach, the first end 218 of the filter member 216 isfixedly connected to the catheter 212, while the second end 220 of thefilter member 216 is movably coupled to the catheter 212 and movesaxially along the catheter 216 upon expansion or contraction of thefilter member 216.

FIG. 18 depicts an embodiment of the filter member 216 identical to thatillustrated in FIG. 19, with the sole exception that the thirdstructural members 219 and the second end 220 of the filter member 216are omitted. In this embodiment, the terminal apex member 227 of eachpetal-like member 225 are not connected to a second end 220 of thefilter member 216 by the third structural members 219.

FIG. 20 depicts an alternative embodiment of the filter member 216 whichis similar to that depicted in FIG. 18, except that at least onecircumferential ring member 252 is connected to the terminal apex member227 of each of the petal-like members 225 at a juncture 253 with theterminal apex member 227. The addition of the additional circumferentialring member 252 results in a relative elongation over the length L1 ofthe filter member 216 depicted in FIG. 18 by a length L2 whichfacilitates additional apposition between the filter member 216 and thevascular wall and stabilization of the petal-like members 225.

FIGS. 21A and 21B depict an alternative embodiment of the filter member216 in FIG. 18, having first end 318, first structural elements 317 andsecond structural elements 319 all analogously arranged as in theembodiment of FIG. 18. Filter member 300, however, employs a modifieddistal end 314 of the catheter 312 to include an expansive balloon 360.The guidewire lumen of the multi-lumen catheter 312 may be used in placeof a distal port for condition sensing, flushing, infusion or the like.The expansive balloon 360 may be used to break up thrombus capturedwithin the filter member 316, either by mechanical force through serialdilatation or by infusion of a thrombolytic agent through openings inthe balloon 360. FIG. 21A depicts the balloon 360 in its collapsedstate, whereas FIG. 21B depicts the balloon in its expanded state.

Alternatively, an expansive balloon 360 may be placed proximal thefilter member 300 and serve to temporarily occlude the vessel tofacilitate aspiration or evacuation of thrombus from the filter member30.

FIGS. 22A and 22B depict an alternative embodiment of the filter member216 in FIG. 20 having first end 418, first structural elements 417 andsecond structural elements 419, at least one circumferential ring member452 connected to the terminal apex member 427 of each of the petal-likemembers 425 at a juncture 453 with the terminal apex member 427; allanalogously arranged as in the embodiment of FIG. 20. Filter member 400,however, employs a modified distal end 414 of the catheter 412 toinclude an expansive balloon 460. The guidewire lumen of the multi-lumencatheter 412 may be used in place of a distal port for conditionsensing, flushing, infusion or the like. The expansive balloon 460 maybe used to break up thrombus captured within the filter member 416,either by mechanical force through serial dilatation or by infusion of athrombolytic agent through openings in the balloon 460. FIG. 22A depictsthe balloon 460 in its collapsed state, whereas FIG. 22B depicts theballoon in its expanded state.

Again, an expansive balloon 460 may be positioned proximal the filtermember 416 to permit temporary occlusion of the blood vessel and permitaspiration or evacuation of thrombus from the filter member 416.

Each of the foregoing embodiments of the present invention may furtherbe adapted for use with an imaging modality to facilitate intravascularimaging of the filter member from beyond or within a lumen of themulti-lumen catheter. Additionally, in some embodiments, the imagingmodality may pass entirely through the distal tip of the multi-lumencatheter, and enable an operator to use the intravascular imagingmodality to visualize the origins of the renal veins. This could allowthe operator to place the catheter without use of external imaging (i.e.fluoroscopy, trans-abdominal duplex ultrasound, CT, etc.).

Generally, intravascular imaging systems utilize a sheath through whicha signal is transmitted and received. In the present invention, themulti-lumen catheter with associated filter member may serve as thesheath for introduction of an intravascular imaging system, permittingimproved imaging of the condition of the filter member while in use. Inparticular, the use of an intravascular imaging system with themulti-lumen catheter with associated filter member will permit a medicalprofessional to monitor the condition of the filter member, and utilizeappropriate techniques to lyse a collected thrombus. Because of theimproved imaging, the lysing techniques may be more specifically andaccurately targeted, as compared to lysing techniques applied withoutthe benefit of imaging the condition of the filter member. In other,alternative, embodiments, the intravascular imaging system may alsoenable a medical professional to visualize the filter catheter forplacement within a patient.

FIG. 23 depicts a cross-sectional side view of one embodiment of theexpanded filter member and catheter assembly of FIG. 12, furthercomprising an imaging modality. In this embodiment, filter member 516consists generally of a first end 518 and a second end 520, each ofwhich consists generally of a tubular structure which iscircumferentially positioned about a section of the catheter body 512.One of the first end 518 and second end 520 are fixedly coupled to thecatheter body 512, while the other is movable relative to the catheterbody 512. The filter member is structurally analogous to that discussedabove, such as in relation to FIG. 12 above. In its unexpanded state thefilter member 516 has a generally tubular shape, while in its expandedstate the filter member 516 assumes one of the general configurationsdiscussed above, i.e., either oppositely extending generally openconical sections or a single generally open conical section. Theassembly may further comprise an outer sheath 522 disposed over thecatheter body 512.

The catheter body 512 includes a distal portion 514 about which thefilter member 516 is disposed. Catheter body 512 further includes atleast one lumen 530, such as a central guidewire lumen, which may extendthe entire longitudinal length of the catheter body 512 and mayterminate at the distal end of the catheter body 512 at a distal opening531. The central lumen 530 may be used to house and/or introduceelements of an imaging system. In another embodiment, the lumen intowhich the imaging system is disposed is not the central lumen, butanother lumen of the multi-lumen catheter body 512, so long as theimaging system is able to image the filter member 516. Some non-limitingexamples of imaging systems include intravascular ultrasound (IVUS),optical coherence tomography (OCT), side looking OCT, ultrasound,thermography, IR imaging, Florence imaging, luminescent imaging, MRI,videography, photoacoustic, and other similar imaging technologies.These systems may permit 360 degree imaging, or be side looking androtatable to image through 360 degrees. In one embodiment, the systemgenerally includes an imaging core drive cable 630 and an imaging probe650. The imaging probe 650 may be a tip, cone, and/or the like disposedat a distal end of the imaging core drive cable 630, wherein the imagingprobe 650 and/or the drive cable 630 are operably connected to anexternal system (not shown) for operating the imaging system.

In one embodiment, the imaging probe 650 may be disposed within aportion 600 of the central lumen 530 bounded by a proximal end 518 and adistal end 520 of the filter member 516. Thus, the imaging probe 650 maybe operated to help a user detect the presence of a thrombus captured bythe filter member 516. Further, the imaging probe 650 may also helpdetect the size and/or position of a captured thrombus. The imagingprobe 650 may be rotated and/or translated within the lumen 530, so asto permit imaging of the entire filter member 516. Alternatively, theimaging probe 650 may be adapted to permit 360 degree imaging of thefilter member 516 without requiring rotation. In a further embodiment,the imaging probe 650 may be adapted to permit imaging of the length ofthe filter member 516 without distal or proximal translation.Preferably, the imaging probe 650 is operable to image the filter member516 in an expanded state.

In one embodiment, the position of the imaging probe 650 relative to thefilter member 516 may be determined. In one embodiment, the imagingprobe 650 may further comprise a radiopaque material to permit externalimaging of the probe 650 to determine its location relative to thefilter 516, which as described above may have its own radiopaquemarkers. In another embodiment, the drive cable 630 may have measuredmarkings disposed thereon to permit determination of the position of theimaging probe 650 relative to the filter 516, based on the relationshipbetween the markings on the drive cable 630 and the conduit into whichthe imaging probe 650 and drive cable 630 are inserted.

In order to monitor the condition of the filter member 516, the imagingprobe 650 may transmit and receive an imaging signal through a wall ofthe lumen 530. The imaging signal may depend upon the particular imagingsystem utilized, and generally comprises a transmitted signal, wave,energy, or the like that is emitted from the imaging probe 650 in orderto image or visualize the filter member 516. In a preferred embodiment,the relevant portion of the lumen 530 is a section 600 of the distalportion 514 of the catheter body 512 bounded by the proximal end 518 anddistal end 520 of the filter member 516. The dimensions and/or materialof any or all of either the bounded portion 600 or the distal portion514 may be selected to maximize imaging signal transmission and/orimaging signal clarity. Examples of appropriate materials include, butare not limited to, polyethylene, PTFE, and other polymers.

Alternatively, in some embodiments the filter 516 may be attached to adistal end of a single or a multi-lumen catheter 512. In theseembodiments, the region bounded by the proximal and distal ends of thefilter 516 is open and free of imaging obstruction. The imaging modalitymay be disposed through the lumen of the catheter 512 and translatedsuch that it extends beyond the distal end of the lumen and into theopen region between the proximal and distal ends of the filter 516.

Where the imaging system is an IVUS system, preferably the portion ofthe catheter body 512 from which the imaging probe 650 images isacoustically transparent to allow for the transmission of the imagingsignal, ultrasound waves for IVUS, through the body 512. The imagingprobe 650 may comprise an ultrasound transducer connected to the distalend of a drive cable 630, which extends through the lumen 530 of thecatheter body 512. The drive cable 630 is used to rotate and translatethe transducer of the imaging probe 650 within the catheter lumen 530.The drive cable 630 may possess a high torsional stiffness so that thedrive cable 630 can transmit torque from a drive motor (not shown) tothe transducer to rotate the transducer. In another embodiment, rotationof the transducer is not necessary, such as when the imaging probe 650is capable of 360 degree imaging. The drive cable 630 may also possess alow bending stiffness allowing the drive to bend along a tortuous pathof a blood vessel. The imaging probe 650 is operably connected toultrasound electronics (not shown) external a patient. In oneembodiment, the operable connection may be via a wire that runs alongthe drive cable 630.

As an optical analog of ultrasound, intravascular OCT uses ahigh-bandwidth light source instead of an ultrasound-emitting crystal tocreate high-resolution images. OCT is an interferometric technique,typically employing near-infrared light, where an optical beam isdirected at tissue, and a small portion of this light that reflects fromsub-surface features is collected. Where the imaging system is an OCTsystem, preferably the portion of the catheter body 512 from withinwhich the imaging probe 650 images is optically transparent to allow forthe transmission of the imaging signal, light waves for OCT, through theportion of the catheter body 512. The imaging probe 650 may comprise anoptical emitter connected to the distal end of a drive cable 630, whichextends through the lumen 530 of the catheter body 512. The drive cable630 is used to rotate and/or translate the optical emitter of theimaging probe 650 within the catheter lumen 530. The imaging probe 650is operably connected to OCT electronics (not shown) external a patient.In one embodiment, the operable connection may be via a wire that runsalong the drive cable 630. In another embodiment, the operableconnection may be via an optical waveguide that runs along the drivecable 630.

Further, the imaging modality may generally be incorporated into any ofthe above disclosed embodiments of the multi-lumen catheter and filtermember assembly.

In another embodiment, an imaging probe may be disposed within a lumenof the IVC filter catheter, without an imaging catheter coupled thereto.

In still another embodiment, an imaging catheter, housing an imagingprobe therein, may be disposed within a lumen of the IVC filtercatheter. In this embodiment, the imaging catheter is not coupled to theIVC filter catheter, and may be disposed within an appropriately sizedlumen of the IVC filter catheter. The imaging modality may thus bepositioned within or beyond a lumen of the IVC filter catheter, as aself-contained system.

In another embodiment, an imaging catheter, housing an imaging coretherein, is integral with a lumen of the IVC filter catheter. Theimaging core may be translated proximally and/or distally relative tothe imaging catheter and/or the IVC filter catheter.

In another embodiment, a medial filter port may be used as a conduit todeliver an imaging catheter to the caval space within the filter. Theimaging catheter may be coupled to the proximal hub of the catheter, byany one of the proximal hubs as disclosed U.S. provisional patentapplication Ser. No. 61/584,716, filed Jan. 9, 2011, U.S. patentapplication Ser. No. 13/083,053, filed Apr. 8, 2011, which are herebyincorporated by reference in their entirety.

In another embodiment, the imaging probe 650 may be disposed within alumen of a multi-lumen catheter sheath, such as that disclosed incommonly owned and co-pending U.S. provisional patent application Ser.No. 61/668,308, filed Jul. 5, 2012, which is hereby incorporated byreference in its entirety. In this embodiment, the imaging probe 650 maybe disposed in the lumen of the multi-lumen sheath rather than thefilter catheter. The imaging probe 650 may be translated so as to bedisposed within a region bounded by the proximal end 518 and distal end520 of the filter member 516. The structure and operation of thisembodiment is analogous to those disclosed above.

Generally, the imaging system may be used with the filter member tomonitor the condition of the filter member and to capture a thrombuswithin a blood vessel. This may be accomplished by introducing themulti-lumen catheter, having the filter member coupled thereto, into theblood vessel. The catheter may then be deployed within the blood vesselsuch that the filter has an enlarged diametric opening facing apatient's blood flow. The imaging system may then be translated througha lumen of the multi-lumen catheter and be operable to image orvisualize the condition of the filter member. If a thrombus is detected,then a fluid may be infused through at least one lumen in themulti-lumen catheter in communication with at least one infusion portpassing through the multi-lumen catheter and open to an inner spatialarea bounded by the filter member. Alternatively, other means of lysinga detected thrombus may be utilized, such as thermal or mechanicallysis, such as by introducing a laser, ultrasound, or other systemcapable of lysing thrombus.

In another embodiment, the imaging system may be used with a multi-lumensheath coupled to a filter catheter, such that the imaging system isdisposed within a lumen of the multi-lumen sheath and images the filtermember.

It will be appreciated by those skilled in the art that in allembodiments of the described central venous access filter, the filtermember has a relatively larger opening that is open inferiorly in adirection that opposes the blood flow vector and employs structuralelements that taper superiorly along the direction of the blood flowvector to reduce the open surface area of the filter member and capturethrombus.

Thus there has been described a central venous access filter inaccordance with the foregoing embodiments of the invention whichinclude, generally, a multi-lumen catheter body, a filter member and anintroducer sheath. The multi-lumen catheter body has a plurality ofports each of which are in fluid flow communication with at least onelumen in the multi-lumen catheter body. Lumens may include a centralguidewire lumen useful for tracking over a guidewire and/or largervolume infusion of bioactive agents, intravenous fluids, bloodtransfusions, or other fluids; infusion lumens in communication withinfusion ports positioned to direct fluids to the space bounded by thefilter member for introducing bioactive agents, including thrombolyticagents or flushing agents, including pressurized fluids for mechanicalthrombolysis directly to the capture site of the thrombus in the filtermember; and lumens communicating with proximal and distal ports whichmay also be used for fluid introduction and/or may house or communicatewith sensors, such as pressure transducers, flow sensors, analytesensors, color sensors, optical sensors or the like. The filter membermay be detachable from the multi-lumen catheter body to permit temporaryfilter placement and later retrieval by a detachment mechanism thatcooperates between the filter and the multi-lumen catheter body. Theseand other aspects of the present invention are provided by way ofnon-limiting examples, with the claims appended hereto serving to definethe scope of the subject matter regarded as the invention.

What is claimed is:
 1. A multi-lumen filter catheter, comprising: a. amulti-lumen catheter body having a plurality of lumens; b. a filtermember fixedly coupled to a distal aspect of the catheter body andoriented to capture thrombus therein; and c. an imaging systempositioned within at least one of the plurality of lumens and positionedproximate the filter member so as to be capable of detecting detect astate of thrombus capture within the filter member.
 2. The multi-lumenfilter catheter according to claim 1, wherein the imaging system isselected from the group comprising an intravascular ultrasound systemand an optical coherence tomography system.
 3. The multi-lumen filtercatheter according to claim 1, wherein the imaging system is disposedwithin a lumen of the multi-lumen catheter body, and the imaging systemis configured to image the filter member from within one of theplurality of lumens of the multi-lumen catheter body.
 4. The multi-lumenfilter catheter according to claim 1, wherein the imaging system furthercomprises a drive cable and a rotatable imaging probe.
 5. Themulti-lumen filter catheter according to claim 4, wherein the imagingprobe is adapted to be positioned within the multi-lumen catheter bodyin a region bounded by a proximal end and a distal end of the filtermember.
 6. The multi-lumen filter catheter according to claim 5, whereinthe bounded region of the multi-lumen catheter body has at least one ofdimensions or material selected to optimize an imaging signaltransmission and an imaging signal clarity therethrough.
 7. Themulti-lumen filter catheter according to claim 4, wherein the imagingprobe is adapted to be longitudinally translated at least one ofproximally or distally relative to the filter member.
 8. The multi-lumenfilter catheter according to claim 4, wherein the imaging system furthercomprises an imaging catheter.
 9. The multi-lumen filter catheteraccording to claim 8, wherein the imaging catheter is disposed within alumen of the multi-lumen catheter body.
 10. The multi-lumen filtercatheter according to claim 8, wherein the imaging catheter is integralwith a lumen of the multi-lumen catheter body.
 11. A medical device,comprising: a. a catheter body having a filter member coupled to thecatheter body, wherein the filter member is circumferentially coupledabout a distal end of the catheter and having a first end coupledcircumferentially in fixed relation to the catheter and a second endcircumferentially moveably coupled to the catheter, the filter memberconsisting of a plurality of struts configured to form a generallyfrustroconical proximal section of the filter member and a generallyfrustroconical distal section of the filter member, the proximal sectionand the distal section of the filter member being asymmetric relative toeach other, the filter member being expandable within a blood vesselsuch that a transverse dimension of the filter decreases in thedirection of the patient's blood flow to collect thrombi within thefilter member; b. a multi-lumen sheath, wherein the catheter body isdisposed within a lumen of the multi-lumen sheath; and c. an imagingsystem operable to detect a condition of the filter member.
 12. Themulti-lumen filter catheter according to claim 11, wherein the imagingsystem is selected from the group comprising an intravascular ultrasoundsystem and an optical coherence tomography system.
 13. The multi-lumenfilter catheter according to claim 12, wherein the imaging system isdisposed within a lumen of the multi-lumen sheath, and the imagingsystem is configured to image the filter member from within said lumenof the multi-lumen sheath.
 14. The multi-lumen filter catheter accordingto claim 11, wherein the imaging system further comprises a drive cableand an imaging probe.
 15. The multi-lumen filter catheter according toclaim 14, wherein the imaging probe is adapted to be positioned withinthe multi-lumen sheath in a region bounded by a proximal end and adistal end of the filter member.
 16. The multi-lumen filter catheteraccording to claim 15, wherein the bounded region of the multi-lumensheath has at least one of dimensions or material selected to optimizean imaging signal transmission and an imaging signal claritytherethrough.
 17. The multi-lumen filter catheter according to claim 14,wherein the imaging probe is adapted to be translated at least one ofproximally or distally relative to the filter member.
 18. Themulti-lumen filter catheter according to claim 14, wherein the imagingprobe is adapted to be rotated relative to the filter member.
 19. Amethod of capturing thrombus within a blood vessel wherein themulti-lumen filter catheter of claim 1 is introduced into a bloodvessel, comprising the steps of: a. deploying the catheter within ablood vessel such that the filter has an enlarged diametric openingwhich opens facing a patient's blood flow; and b. imaging the filtermember with an imaging system operable to detect a condition of thefilter member.
 20. The method according to claim 19, wherein the step ofimaging the filter member further comprises confirming the presence of athrombus captured by the filter member.
 21. The method according toclaim 19, wherein the imaging system is selected from the groupcomprising an intravascular ultrasound system and an optical coherencetomography system.
 22. The method according to claim 19, wherein thestep of imaging the filter member further comprises inserting theimaging system into a lumen of the catheter and disposing an imagingprobe of the imaging system in a region of the catheter bounded by aproximal end and a distal end of the filter member.
 23. The methodaccording to claim 22, wherein the imaging probe is adapted to betranslated at least one of proximally or distally relative to the filtermember.
 24. The method according to claim 22, wherein the imaging probeis adapted to be rotated relative to the filter member.
 25. The methodaccording to claim 19, wherein the step of introducing a catheterfurther comprises disposing the catheter in a lumen of a multi-lumensheath, and introducing the multi-lumen sheath having the catheterdisposed therein.
 26. The method according to claim 25, wherein theimaging system is disposed within a lumen of the multi-lumen sheath.